Designing local standard growth charts of children in East Java province using a local linear estimator

In this study we propose new designs of standard growth charts of children called a local standard growth chart (LSGC) which is significantly more suitable for children aged up to five years old in the East Java province of Indonesia than the WHO-2005 standard growth chart (WSGC), to assess their nutrition status. The proposed designs are LSGC of weight, LSGC of height and LSGC of BMI which are based on age by using a sample of children aged up to five years from East Java province. Children around one year old grow up rapidly then slowly. Also, growth patterns of boys and girls are different. Hence, we use predictor variables that consist of sex as a parametric component and age as a nonparametric component, leading to a semiparametric local linear model approach for constructing LSGC. Results show that the obtained median models of LSGC have satisfied the goodness of model fitting criterions, that include determining coefficient (R2) of 0.997 and mean squared error of 0.21. In addition, the percentage of normal status of nutrition for children is considered province based on LSGC which are higher than those based on WSGC. LSGC can be used by the Government for assessing the status of nutrition of children from East Java.